package com.hmdp.service.impl;

import com.hmdp.dto.Result;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import org.springframework.aop.framework.AopContext;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;
import java.time.LocalDateTime;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;
    @Resource
    private RedisIdWorker redisIdWorker;
    /**
     * 优惠券秒杀
     * @param voucherId
     * @return
     */
    @Override
    public Result seckillVoucher(Long voucherId) {
        // 1.根据id查询优惠卷信息
        SeckillVoucher seckillVoucher = seckillVoucherService.getById(voucherId);
        // 2.判断秒杀是否开始
        if(seckillVoucher.getBeginTime().isAfter(LocalDateTime.now())){
            return Result.fail("秒杀尚未开始");
        }
        if(seckillVoucher.getEndTime().isBefore(LocalDateTime.now())){
            return Result.fail("秒杀已经结束");
        }
        // 如果没开始 返回异常信息 报错
        // 如果开始了，判断库存是否充足
        if(seckillVoucher.getStock()<1){
            // 如果不足 返回
            return Result.fail("库存不足");
        }
        //  第三种 锁的释放是在提交事务（方法执行完）之后
        Long userId = UserHolder.getUser().getId();
        synchronized (userId.toString().intern()) {
            // 获取代理对象(跟事务有关)
            IVoucherOrderService  proxy = (IVoucherOrderService)AopContext.currentProxy();
            return proxy.createVoucherOrder(voucherId);
        }
    }
    @Transactional
    public  Result createVoucherOrder(Long voucherId) {
        // 一人一单
        Long userId = UserHolder.getUser().getId();

            // 查询订单
            Integer count = query().eq("user_id", userId)
                    .eq("voucher_id", voucherId).count();
            // 判断是否存在
            if (count > 0) {
                return Result.fail("该用户已经购买过");
            }
            // 如果充足 扣减库存
            boolean success = seckillVoucherService.update()
                    .setSql("stock=stock-1")
                    .eq("voucher_id", voucherId).gt("stock", 0)
                    .update();
            if (!success) {
                return Result.fail("库存不足");
            }

            // 创建订单
            VoucherOrder voucherOrder = new VoucherOrder();
            // 订单id
            long orderId = redisIdWorker.nextId("order");
            voucherOrder.setId(orderId);

            // 用户id
            /* Long userId = UserHolder.getUser().getId();*/
            voucherOrder.setUserId(userId);

            // 优惠卷id
            voucherOrder.setVoucherId(voucherId);
            //结束
            save(voucherOrder);
            return Result.ok(orderId);

        }

}
